We are a machine shop sending several batches of sandblasted aluminum for clear anodizing per week to a supplier. We've recently had a major problem where the anodized parts are becoming yellow after a short period of time (1-2 weeks). The yellow is only on the surface and is easily cleaned with "Windex" or any other cleaner.
When we received the parts from anodizing, they are always inspected and are not yellow, this happens after. I have raised the issue with my supplier and they have no idea so I am asking this question here instead.
